kernel/linux.git/fs/smb, branch v6.18.33

smb: client: Use FullSessionKey for AES-256 encryption key derivation

2026-05-23T11:07:20+00:00

[ Upstream commit 5be7a0cef3229fb3b63a07c0d289daf752545424 ] When Kerberos authentication is used with AES-256 encryption (AES-256-CCM or AES-256-GCM), the SMB3 encryption and decryption keys must be derived using the full session key (Session.FullSessionKey) rather than just the first 16 bytes (Session.SessionKey). Per MS-SMB2 section 3.2.5.3.1, when Connection.Dialect is "3.1.1" and Connection.CipherId is AES-256-CCM or AES-256-GCM, Session.FullSessionKey must be set to the full cryptographic key from the GSS authentication context. The encryption and decryption key derivation (SMBC2SCipherKey, SMBS2CCipherKey) must use this FullSessionKey as the KDF input. The signing key derivation continues to use Session.SessionKey (first 16 bytes) in all cases. Previously, generate_key() hardcoded SMB2_NTLMV2_SESSKEY_SIZE (16) as the HMAC-SHA256 key input length for all derivations. When Kerberos with AES-256 provides a 32-byte session key, the KDF for encryption/decryption was using only the first 16 bytes, producing keys that did not match the server's, causing mount failures with sec=krb5 and require_gcm_256=1. Add a full_key_size parameter to generate_key() and pass the appropriate size from generate_smb3signingkey(): - Signing: always SMB2_NTLMV2_SESSKEY_SIZE (16 bytes) - Encryption/Decryption: ses->auth_key.len when AES-256, otherwise 16 Also fix cifs_dump_full_key() to report the actual session key length for AES-256 instead of hardcoded CIFS_SESS_KEY_SIZE, so that userspace tools like Wireshark receive the correct key for decryption. Cc: Reviewed-by: Bharath SM Signed-off-by: Piyush Sachdeva Signed-off-by: Piyush Sachdeva Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

smb/client: fix possible infinite loop and oob read in symlink_data()

2026-05-23T11:07:17+00:00

commit 7d9a7f1f96cd617ee9e75bb22217c709038e26b8 upstream. On 32-bit architectures, the infinite loop is as follows: len = p->ErrorDataLength == 0xfffffff8 u8 *next = p->ErrorContextData + len next == p On 32-bit architectures, the out-of-bounds read is as follows: len = p->ErrorDataLength == 0xfffffff0 u8 *next = p->ErrorContextData + len next == (u8 *)p - 8 Reported-by: ChenXiaoSong Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Cc: stable@vger.kernel.org Signed-off-by: Ye Bin Reviewed-by: ChenXiaoSong Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

ksmbd: scope conn->binding slowpath to bound sessions only

2026-05-23T11:07:03+00:00

[ Upstream commit b0da97c034b6107d14e537e212d4ce8b22109a58 ] When the binding SESSION_SETUP sets conn->binding = true, the flag stays set after the call so that the global session lookup in ksmbd_session_lookup_all() can find the session, which was not added to conn->sessions. Because the flag is connection-wide, the global lookup path will also resolve any other session by id if asked. Tighten the global lookup so that the returned session must have this connection registered in its channel xarray (sess->ksmbd_chann_list). The channel entry is installed by the existing binding_session path in ntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes successfully, so this condition is a strict equivalent of "this connection has been accepted as a channel of this session". Connections that have not bound to a given session cannot reach it via the global table. The existing conn->binding gate for entering the slowpath is preserved so that non-binding connections keep the fast-path-only behavior, and the session->state check is unchanged. Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Signed-off-by: Hyunwoo Kim Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: fix durable fd leak on ClientGUID mismatch in durable v2 open

2026-05-23T11:07:03+00:00

[ Upstream commit 804054d19886ac6628883d82410f6ee42a818664 ] ksmbd_lookup_fd_cguid() returns a ksmbd_file with its refcount incremented via ksmbd_fp_get(). parse_durable_handle_context() in the DURABLE_REQ_V2 case properly releases this reference on every path inside the ClientGUID-match branch, either by calling ksmbd_put_durable_fd() or by transferring ownership to dh_info->fp for a successful reconnect. However, when an entry exists in the global file table with the same CreateGuid but a different ClientGUID, the code simply falls through to the new-open path without dropping the reference obtained from ksmbd_lookup_fd_cguid(). Per MS-SMB2 section 3.3.5.9.10 ("Handling the SMB2_CREATE_DURABLE_HANDLE_REQUEST_V2 Create Context"), the server MUST locate an Open whose Open.CreateGuid matches the request's CreateGuid AND whose Open.ClientGuid matches the ClientGuid of the connection that received the request. If no such Open is found, the server MUST continue with the normal open execution phase. A CreateGuid hit with a ClientGUID mismatch is therefore the "Open not found" case: proceeding with a new open is correct, but the reference obtained purely as a side effect of the lookup must not be leaked. Repeated requests that hit this mismatch pin global_ft entries, prevent __ksmbd_close_fd() from ever running for the corresponding files, and defeat the durable scavenger, leading to long-lived resource leaks. Release the reference in the mismatch path and clear dh_info->fp so subsequent logic does not mistake a non-matching lookup result for a reconnect target. Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Signed-off-by: DaeMyung Kang Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: destroy async_ida in ksmbd_conn_free()

2026-05-23T11:07:03+00:00

[ Upstream commit b32c8db48212a34998c36d0bbc05b29d5c407ef5 ] When per-connection async_ida was converted from a dynamically allocated ksmbd_ida to an embedded struct ida, ksmbd_ida_free() was removed from the connection teardown path but no matching ida_destroy() was added. The connection is therefore freed with the IDA's backing xarray still intact. The kernel IDA API expects ida_init() and ida_destroy() to be paired over an object's lifetime, so add the missing cleanup before the connection is freed. No leak has been observed in testing; this is a pairing fix to match the IDA lifetime rules, not a response to a reproduced regression. Fixes: d40012a83f87 ("cifsd: declare ida statically") Signed-off-by: DaeMyung Kang Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: destroy tree_conn_ida in ksmbd_session_destroy()

2026-05-23T11:07:03+00:00

[ Upstream commit c049ee14eb4343b69b6f7755563f961f5e153423 ] When per-session tree_conn_ida was converted from a dynamically allocated ksmbd_ida to an embedded struct ida, ksmbd_ida_free() was removed from ksmbd_session_destroy() but no matching ida_destroy() was added. The session is therefore freed with the IDA's backing xarray still intact. The kernel IDA API expects ida_init() and ida_destroy() to be paired over an object's lifetime, so add the missing cleanup before the enclosing session is freed. Also move ida_init() to right after the session is allocated so that it is always paired with the destroy call even on the early error paths of __session_create() (ksmbd_init_file_table() or __init_smb2_session() failures), both of which jump to the error label and invoke ksmbd_session_destroy() on a partially initialised session. No leak has been observed in testing; this is a pairing fix to match the IDA lifetime rules, not a response to a reproduced regression. Fixes: d40012a83f87 ("cifsd: declare ida statically") Signed-off-by: DaeMyung Kang Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: fix use-after-free in smb2_open during durable reconnect

2026-05-23T11:07:00+00:00

[ Upstream commit 1baff47b81f94f9231c91236aa511420d0e266b9 ] In smb2_open, the call to ksmbd_put_durable_fd(fp) drops the reference to the durable file descriptor early during the durable reconnect process. If an error occurs subsequently (eg, ksmbd_iov_pin_rsp fails) or a scavenger accesses the file, it leads to a use-after-free when accessing fp properties (eg fp->create_time). Move the single put to the end of the function below err_out2 so fp stays valid until smb2_open returns. Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Signed-off-by: Akif Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

smb: move smb_version_values to common/smbglob.h

2026-05-23T11:07:00+00:00

[ Upstream commit 34cf191bb6a349dc88ec2c4f6355fe006ac669e0 ] Merge the struct members of the server and the client: - req_capabilities: from client - header_preamble_size: from client - cap_unicode: from client - capabilities: from server, rename to req_capabilities - max_read_size: from server - max_write_size: from server - max_trans_size: from server - max_credits: from server - create_durable_size: from server - create_durable_v2_size: from server - create_mxac_size: from server - create_disk_id_size: from server - create_posix_size: from server Then move duplicate definitions to common header file. Co-developed-by: ChenXiaoSong Signed-off-by: ChenXiaoSong Signed-off-by: ZhangGuoDong Acked-by: Namjae Jeon Signed-off-by: Steve French Stable-dep-of: 1baff47b81f9 ("ksmbd: fix use-after-free in smb2_open during durable reconnect") Signed-off-by: Sasha Levin

ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine

2026-05-23T11:06:44+00:00

[ Upstream commit 3e298897f41c61450c2e7a4f457e8b2485eb35b3 ] ksmbd_crypt_message() sets a NULL completion callback on AEAD requests and does not handle the -EINPROGRESS return code from async hardware crypto engines like the Qualcomm Crypto Engine (QCE). When QCE returns -EINPROGRESS, ksmbd treats it as an error and immediately frees the request while the hardware DMA operation is still in flight. The DMA completion callback then dereferences freed memory, causing a NULL pointer crash: pc : qce_skcipher_done+0x24/0x174 lr : vchan_complete+0x230/0x27c ... el1h_64_irq+0x68/0x6c ksmbd_free_work_struct+0x20/0x118 [ksmbd] ksmbd_exit_file_cache+0x694/0xa4c [ksmbd] Use the standard crypto_wait_req() pattern with crypto_req_done() as the completion callback, matching the approach used by the SMB client in fs/smb/client/smb2ops.c. This properly handles both synchronous engines (immediate return) and async engines (-EINPROGRESS followed by callback notification). Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Link: https://github.com/openwrt/openwrt/issues/21822 Signed-off-by: Joshua Klinesmith Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: validate inherited ACE SID length

2026-05-14T13:30:26+00:00

commit 996454bc0da84d5a1dedb1a7861823087e01a7ae upstream. smb_inherit_dacl() walks the parent directory DACL loaded from the security descriptor xattr. It verifies that each ACE contains the fixed SID header before using it, but does not verify that the variable-length SID described by sid.num_subauth is fully contained in the ACE. A malformed inheritable ACE can advertise more subauthorities than are present in the ACE. compare_sids() may then read past the ACE. smb_set_ace() also clamps the copied destination SID, but used the unchecked source SID count to compute the inherited ACE size. That could advance the temporary inherited ACE buffer pointer and nt_size accounting past the allocated buffer. Fix this by validating the parent ACE SID count and SID length before using the SID during inheritance. Compute the inherited ACE size from the copied SID so the size matches the bounded destination SID. Reject the inherited DACL if size accumulation would overflow smb_acl.size or the security descriptor allocation size. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Signed-off-by: Shota Zaizen Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman